1. From the Department of Ophthalmology, School of Medicine, Sapporo Medical University, Sapporo, Japan;
2. Oral Health Science Center and Department of Anatomy, Tokyo Dental College, Tokyo, Japan;
3. Department of Anatomy and Embryology II, Faculty of Medicine, Complutense University, Madrid, Spain; and
4. the Division of Internal Medicine, Iwamizawa Kojin-kai Hospital, Iwamizawa, Japan.